Can natural selection keep up?

[FreeThinker]

Since the emergence of our ability to understand and manipulate the world, humans have been changing the face of the planet. It is not just ourselves that we are affecting. In the same way that natural selection has been applying pressure on life for millions of years, humans have been doing so more recently. An important difference between natural and Homo sapien selection (H.S.S) is that the later is happening at a much faster rate.

 

Our ability to travel around the globe in short period of time has altered many ecosystems around the world. Rats, cats, dogs, foxes etc are all common companions to traveling humans. Once transferred to a foreign location, local animals have to adapt to the intruders. They have to adapt to the Homo sapien way. In Australia, the domestic animals are being driven to extinction by the feral cats and rabbits. Undoubted, natural selection has a role to play in this. But does natural selection have enough time to act? How might animals, if at all, adapt to this HSS selection pressure? Can natural selection compete with HSS selection? Only victory I see for natural selection is the parasites that infect humans. This is perhaps the best example of the arm race between HSS and natural selection. The HIV virus is an example of nature being able to act at extremely fast speed. But is such fast selection always doomed for the simplest of forms of life? I am assuming here that viruses are a form of life, which would be inaccurate according to many definitions. If you don’t consider viruses a form of life, can nature keep up at all? Are any animals that are affected by H.S.S, capable of adapting?

[Dr. Dalek]

Humans are certainly influencing the way that animals develop and are selected for. However natural selection is certainly not something we directly control.

I should think the reason that we humans cause problems in the world around us is that unlike other animals who have well developed instincts and natural habits, we humans have no idea what we are doing. However acting creatively has cause things such as pollution (which always represented a lack of efficiency on our part).

Animals do have to adapt to us and I have no doubt that they can.

After all there were problems faced by other animals long before we humans reached our current massive population, some of those problems were thousands of times worse than anything we have done due to our lack of efficiency.

One example of animals adapting to the presence of man is the Eastern Coyote.

Eastern Coyote

 

An apparently recent arrival in the forests of the northeastern US, this relatively new sub-species has moved into the ecological niche-- mid-to-large social predator-- left vacant by the absence of timber wolf and mountain lion.

 

It is a somewhat larger and social animal than the Western coyote. There was some hybridization with wolves, and, perhaps, dogs. The Coyote is more adept at living close to people than wolves.

 

Coyotes are almost completely unprotected, but they are extremely adaptable, and, despite periodic attempts at extermination, continue to expand their range. One factor in their resilience: as population decreases, litter size increases.

 

Retrieved from "http://en.wikipedia.org/wiki/Northeast_coyote"

In this case it seems that the coyotes and the wolves, in effect "survived" by hybridizing resulting in a new subspecies that filled the ecological niche left by the wolf.

I would assume that human selective pressures are to a certain extent outside the norm for the natural world, but not even close to possible catastrophic natural disasters that have been occurring for about four billion years.

I sure that as new technology developes, polution problems will eventualy level out. Human population on the other hand, I'm not so sure about.

[FreeThinker]

I have no doubt that introduced animals can adapt to their new environments. However, how do local species adapt to the introduced animals. For example, the coyote in your example might be adapting well but how are other predators in that area adapting to the coyote? Even if the other predators did adapt to the coyote, surely it’s a rare case. Introduced species often cause irreversible damage. Foxes, rabbits, feral pigs cause havoc in just about every place where they are introduced. At the very least it leads to the extinction of local species. I guess the real question is how much long term damage does it cause to the ecosystem? You could argue that the environment will change by simply adapting to the introduced species. But in that case we shouldn’t worry about any animals going extinct because the environment can adapt and possibly provide a path for new species to evolve.

[Dr. Dalek]

Inspite of the coyotes the deer are doing well, foxes are prevelent, and rabbits are making a comeback. I don't know about other preadators.

I'll do some reasearch and get back to you.

[Dr. Dalek]

I found a website!

Finally

 

http://texnat.tamu.edu/symposia/coyote/p6.htm

 

It seems that coyotes aren't entirly detrimental. They said that like any other preadator they either coexist or compete with other animals.

Habitat and food resources are similar, although the coyote typically utilizes a wider range of food items. Larger predators generally select larger prey, allowing predators of different sizes to coexist, . . . No studies have identified coyote predation as a cause for limiting or decreasing other predator populations, . .

Another website indicates that Coyotes displace foxes and can reduce their population, but foxes are still found in coyote territories.

http://www2.bc.edu/~wayjo/OtherWildlife.html

 

So the other preadators don't seem to have much of a problem with the coyotes.

It appears, at least in this case, that natural selection has kept up

[SkepticLance]

Free Thinker.

Since you are Australian, I suggest you lay your hands on a book called "The New Nature" by a fellow Ozzie, Tim Lowe. Excellent book, which relates to the impacts of humans on natural ecosystems, emphasizing Australia.

 

Your views are essentially correct and well considered. The introduction of alien species into areas where vulnerable species can be affected seems to be the main mechanism by which humans disrupt said ecosystems. Australia's introduced foxes are a prime example.

 

No-one can answer your questions. We simply do not know. The speed of adaptation and evolution into new species is very varied and very uncertain. Many species cannot adapt to such immense shocks as rats on Lord Howe Island (I was there recently), and simply go extinct. Others diminish in number and slowly adapt.

 

Personally, I think (from theory, rather than more reliable empirical evidence) that the world today has begun a massive speciation event, with thousands, or even millions, of new species slowly developing in response to what man has done. I predict that, when genome analysis becomes quick and cheap, that we will be able to plot these genetic changes in wild populations.

[bombus]

I am not sure what you mean by asking 'can natural selection keep up'.

Natural selection is just a process and runs as fast or slow as the the situations dictate. The more 'virulent' the problem, the quicker an adaptive 'solution' is found. If none is found the species goes extinct.

 

Being able to adapt to human impacts (such as species introduced by humans) is really just another selection test. How 'natural' that selection test is depends on your meaning of the term 'natural' (is man 'natural?')

 

If you are asking 'will lots of species go extinct in the near future as a result of humans moving organisms around the planet?' the answer is YES! One could simply argue that it's nothing to worry about as new species will emerge if given enough time - and that is true. However, I'd rather live in a world with tigers, elephants, rhinos, chimps, etc, rather than just cats, dogs, rats and humans!

 

Conservation is a religion, and I am one of its preachers...